China Aster in Zone 10a & 10b
Callistephus chinensis
When to plant china aster in zone 10b
Zones 10a and 10b share the same average frost dates in our data, so this page covers both.
Method: Start indoors: Start indoors from seed, then transplant outside. China Aster needs a head start most zones can't give it by direct-sowing alone.
| Start indoors | Dec 12–Dec 19 |
|---|---|
| Direct sow / transplant outside | Feb 6–Feb 13 |
| Estimated bloom | May 7–May 14 (~90 days after transplanting) |
Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 1.5-2.5 ft.

China aster is not related to the perennial garden asters despite the common name; it's a true annual grown from seed each year for its full, peony-like cut-flower blooms.
How china aster fits zone 10's season
Zone 10b's frost-free window runs about 324 days, from January 30 to December 20. China Aster needs about 90 days from transplant to first harvest.
Good companions
No standout companions recorded yet for China Aster.
Where to buy china aster seeds
See why we recommend these suppliers →
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See it growing
Search YouTube for "growing china aster" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
← Back to the full zone 10b calendar · Full companion planting guide · Full plant profile · Plan your beds in the Garden Designer →

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Growing China Aster in USDA zone 10b: when to start seeds indoors, when to direct-sow, and when to expect a bloom.
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